Preheat your oven to 200°C (390°F). Scrub the potatoes clean, prick them several times with a fork, and rub a little olive oil over the skin. Sprinkle with coarse salt.

Bake the potatoes directly on the oven rack for 60-90 minutes, or until they are tender when squeezed. The cooking time will vary based on potato size.

While potatoes bake, prepare the mushroom ragout. Clean the mushrooms and slice or tear larger ones into bite-sized pieces.

In a large pan over medium-high heat, melt the butter and add the olive oil. Add the sliced mushrooms and cook, stirring occasionally, until they release their liquid and begin to brown, about 8-10 minutes.

Add the diced shallot and minced garlic to the pan with the mushrooms. Sauté for another 2-3 minutes until the shallot softens and becomes fragrant.

Pour in the white wine (or vegetable broth) and scrape up any browned bits from the bottom of the pan. Let it simmer until the liquid has mostly evaporated, about 3-5 minutes.

Stir in the crème fraîche and grated Parmesan cheese. Cook for 1-2 minutes, just until the sauce thickens slightly and the cheese has melted. Season with salt and pepper to taste.

Remove the pan from the heat and stir in the chopped fresh parsley and truffle oil. Taste and adjust seasoning and truffle oil as desired.

For the baguette, lightly brush the slices with olive oil and toast them in the oven for the last 5-7 minutes of the potato's cooking time, or until golden and crisp.

Once the potatoes are cooked, carefully cut a cross into the top of each potato. Fluff the inside flesh with a fork.

Spoon a generous amount of the wild mushroom and truffle ragout over each baked potato. Serve immediately with the toasted baguette slices on the side.